1. Technical Field
The present invention relates to a modulation apparatus, a test apparatus, and a correction method.
2. Related Art
Japanese Patent Application Publication No. 2005-244358 discloses a method for measuring error of a quadrature modulator.
In recent years, quadrature modulators with high speed and high precision are greatly desired. When using a high-speed high-precision quadrature modulator, it is necessary to adjust the accuracy using an adjustment circuit before using the quadrature modulator. However, since the quadrature modulator is an analog circuit, providing the adjustment circuit increases the overall circuit size. Furthermore, the quadrature modulator requires a longer time for adjustment when there are many adjustments to be made.